/* $Id: ip27-irq.c,v 1.9 2000/03/14 01:39:27 ralf Exp $ * * ip27-irq.c: Highlevel interrupt handling for IP27 architecture. * * Copyright (C) 1999 Ralf Baechle (ralf@gnu.org) * Copyright (C) 1999 Silicon Graphics, Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Linux has a controller-independent x86 interrupt architecture. * every controller has a 'controller-template', that is used * by the main code to do the right thing. Each driver-visible * interrupt source is transparently wired to the apropriate * controller. Thus drivers need not be aware of the * interrupt-controller. * * Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC, * PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC. * (IO-APICs assumed to be messaging to Pentium local-APICs) * * the code is designed to be easily extended with new/different * interrupt controllers, without having to do assembly magic. */ irq_cpustat_t irq_stat [NR_CPUS]; extern asmlinkage void ip27_irq(void); int (*irq_cannonicalize)(int irq); unsigned int local_bh_count[NR_CPUS]; unsigned int local_irq_count[NR_CPUS]; unsigned long spurious_count = 0; /* * we need to map irq's up to at least bit 7 of the INT_MASK0_A register * since bits 0-6 are pre-allocated for other purposes */ #define IRQ_TO_SWLEVEL(i) i + 7 #define SWLEVEL_TO_IRQ(s) s - 7 void disable_irq(unsigned int irq_nr) { panic("disable_irq() called ..."); } void enable_irq(unsigned int irq_nr) { panic("enable_irq() called ..."); } /* This is stupid for an Origin which can have thousands of IRQs ... */ static struct irqaction *irq_action[NR_IRQS]; int get_irq_list(char *buf) { int i, len = 0; struct irqaction * action; for (i = 0 ; i < 32 ; i++) { action = irq_action[i]; if (!action) continue; len += sprintf(buf+len, "%2d: %8d %c %s", i, kstat.irqs[0][i], (action->flags & SA_INTERRUPT) ? '+' : ' ', action->name); for (action=action->next; action; action = action->next) { len += sprintf(buf+len, ",%s %s", (action->flags & SA_INTERRUPT) ? " +" : "", action->name); } len += sprintf(buf+len, "\n"); } return len; } /* * do_IRQ handles all normal device IRQ's (the special SMP cross-CPU interrupts * have their own specific handlers). */ asmlinkage void do_IRQ(int irq, struct pt_regs * regs) { struct irqaction *action; int do_random, cpu; cpu = smp_processor_id(); irq_enter(cpu, irq); kstat.irqs[cpu][irq]++; action = *(irq + irq_action); if (action) { if (!(action->flags & SA_INTERRUPT)) __sti(); action = *(irq + irq_action); do_random = 0; do { do_random |= action->flags; action->handler(irq, action->dev_id, regs); action = action->next; } while (action); if (do_random & SA_SAMPLE_RANDOM) add_interrupt_randomness(irq); __cli(); } irq_exit(cpu, irq); /* unmasking and bottom half handling is done magically for us. */ } /* * Find first bit set */ static int ms1bit(unsigned long x) { int b; if (x >> 32) b = 32, x >>= 32; else b = 0; if (x >> 16) b += 16, x >>= 16; if (x >> 8) b += 8, x >>= 8; if (x >> 4) b += 4, x >>= 4; if (x >> 2) b += 2, x >>= 2; return b + (int) (x >> 1); } /* For now ... */ void ip27_do_irq(struct pt_regs *regs) { int irq, swlevel; hubreg_t pend0, mask0; /* copied from Irix intpend0() */ while (((pend0 = LOCAL_HUB_L(PI_INT_PEND0)) & (mask0 = LOCAL_HUB_L(PI_INT_MASK0_A))) != 0) { do { swlevel = ms1bit(pend0); LOCAL_HUB_S(PI_INT_MASK0_A, mask0 & ~(1 << swlevel)); LOCAL_HUB_S(PI_INT_PEND_MOD, swlevel); LOCAL_HUB_L(PI_INT_MASK0_A); /* Flush */ /* "map" swlevel to irq */ irq = SWLEVEL_TO_IRQ(swlevel); do_IRQ(irq, regs); /* reset INT_MASK0 register */ LOCAL_HUB_S(PI_INT_MASK0_A, mask0); /* clear bit in pend0 */ pend0 ^= 1ULL << swlevel; } while (pend0); } } /* Startup one of the (PCI ...) IRQs routes over a bridge. */ static unsigned int bridge_startup(unsigned int irq) { bridge_t *bridge = (bridge_t *) 0x9200000008000000; bridgereg_t br; int pin, swlevel; /* FIIIIIXME ... Temporary kludge. This knows how interrupts are setup in _my_ Origin. */ switch (irq) { case QLOGICFC_SLOT5: pin = 5; break; case IOC3_SERIAL_INT: pin = 3; break; case IOC3_ETH_INT: pin = 2; break; case SCSI1_INT: pin = 1; break; case SCSI0_INT: pin = 0; break; default: panic("bridge_startup: whoops?"); } /* * "map" irq to a swlevel greater than 6 since the first 6 bits * of INT_PEND0 are taken */ swlevel = IRQ_TO_SWLEVEL(irq); br = LOCAL_HUB_L(PI_INT_MASK0_A); LOCAL_HUB_S(PI_INT_MASK0_A, br | (1 << swlevel)); LOCAL_HUB_L(PI_INT_MASK0_A); /* Flush */ bridge->b_int_addr[pin].addr = 0x20000 | swlevel; bridge->b_int_enable |= (1 << pin); if (irq < 2 || irq==5) { bridgereg_t device; #if 0 /* * Allocate enough RRBs on the bridge for the DMAs. * Right now allocating 2 RRBs on the normal channel * and 2 on the virtual channel for slot 0 on the bus. * And same for slot 1, to get ioc3 eth working. */ Not touching b_even_resp /* boot doesn't go far */ bridge->b_even_resp = 0xdd99cc88; /* boot doesn't go far */ bridge->b_even_resp = 0xcccc8888; /* breaks eth0 */ bridge->b_even_resp = 0xcc88; /* breaks eth0 */ #endif /* Turn on bridge swapping */ device = bridge->b_device[irq].reg; device |= BRIDGE_DEV_SWAP_DIR; bridge->b_device[irq].reg = device; /* * Associate interrupt pin with device * XXX This only works if b_int_device is initialized to 0! */ device = bridge->b_int_device; device |= (pin << (irq*3)); bridge->b_int_device = device; } bridge->b_widget.w_tflush; /* Flush */ return 0; /* Never anything pending. */ } /* Shutdown one of the (PCI ...) IRQs routes over a bridge. */ static unsigned int bridge_shutdown(unsigned int irq) { bridge_t *bridge = (bridge_t *) 0x9200000008000000; bridgereg_t br; int pin, swlevel; /* FIIIIIXME ... Temporary kludge. This knows how interrupts are setup in _my_ Origin. */ switch (irq) { case QLOGICFC_SLOT5: pin = 5; break; case IOC3_SERIAL_INT: pin = 3; break; case IOC3_ETH_INT: pin = 2; break; case SCSI1_INT: pin = 1; break; case SCSI0_INT: pin = 0; break; default: panic("bridge_startup: whoops?"); } /* * map irq to a swlevel greater than 6 since the first 6 bits * of INT_PEND0 are taken */ swlevel = IRQ_TO_SWLEVEL(irq); br = LOCAL_HUB_L(PI_INT_MASK0_A); br = LOCAL_HUB_L(PI_INT_MASK0_A); LOCAL_HUB_S(PI_INT_MASK0_A, br & ~(1 << swlevel)); LOCAL_HUB_L(PI_INT_MASK0_A); /* Flush */ bridge->b_int_enable &= ~(1 << pin); bridge->b_widget.w_tflush; /* Flush */ return 0; /* Never anything pending. */ } static void bridge_init(void) { bridge_t *bridge = (bridge_t *) 0x9200000008000000; /* Hmm... IRIX sets additional bits in the address which are documented as reserved in the bridge docs ... */ bridge->b_int_mode = 0x0; /* Don't clear ints */ #if 0 bridge->b_wid_int_upper = 0x000a8000; /* Ints to node 0 */ bridge->b_wid_int_lower = 0x01000090; bridge->b_dir_map = 0xa00000; /* DMA */ #endif /* shouldn't lower= 0x01800090 ??? */ bridge->b_wid_int_upper = 0x00098000; /* Ints to node 0 */ bridge->b_wid_int_lower = 0x01800090; bridge->b_dir_map = 0x900000; /* DMA */ bridge->b_int_enable = 0; bridge->b_widget.w_tflush; /* Flush */ set_cp0_status(SRB_DEV0 | SRB_DEV1, SRB_DEV0 | SRB_DEV1); } void irq_debug(void) { bridge_t *bridge = (bridge_t *) 0x9200000008000000; printk("bridge->b_int_status = 0x%x\n", bridge->b_int_status); printk("bridge->b_int_enable = 0x%x\n", bridge->b_int_enable); printk("PI_INT_PEND0 = 0x%x\n", LOCAL_HUB_L(PI_INT_PEND0)); printk("PI_INT_MASK0_A = 0x%x\n", LOCAL_HUB_L(PI_INT_MASK0_A)); } int setup_irq(unsigned int irq, struct irqaction *new) { int shared = 0; struct irqaction *old, **p; unsigned long flags; if (new->flags & SA_SAMPLE_RANDOM) rand_initialize_irq(irq); save_and_cli(flags); p = irq_action + irq; if ((old = *p) != NULL) { /* Can't share interrupts unless both agree to */ if (!(old->flags & new->flags & SA_SHIRQ)) { restore_flags(flags); return -EBUSY; } /* Add new interrupt at end of irq queue */ do { p = &old->next; old = *p; } while (old); shared = 1; } *p = new; if (!shared) { bridge_startup(irq); } restore_flags(flags); return 0; } int request_irq(unsigned int irq, void (*handler)(int, void *, struct pt_regs *), unsigned long irqflags, const char * devname, void *dev_id) { int retval; struct irqaction *action; if (irq > 9) return -EINVAL; if (!handler) return -EINVAL; action = (struct irqaction *)kmalloc(sizeof(*action), GFP_KERNEL); if (!action) return -ENOMEM; action->handler = handler; action->flags = irqflags; action->mask = 0; action->name = devname; action->next = NULL; action->dev_id = dev_id; retval = setup_irq(irq, action); if (retval) kfree(action); return retval; } void free_irq(unsigned int irq, void *dev_id) { struct irqaction * action, **p; unsigned long flags; if (irq > 9) { printk("Trying to free IRQ%d\n", irq); return; } for (p = irq + irq_action; (action = *p) != NULL; p = &action->next) { if (action->dev_id != dev_id) continue; /* Found it - now free it */ save_and_cli(flags); *p = action->next; if (!irq[irq_action]) bridge_shutdown(irq); restore_flags(flags); kfree(action); return; } printk("Trying to free free IRQ%d\n",irq); } /* Useless ISA nonsense. */ unsigned long probe_irq_on (void) { panic("probe_irq_on called!\n"); return 0; } int probe_irq_off (unsigned long irqs) { return 0; } static int indy_irq_cannonicalize(int irq) { return irq; /* Sane hardware, sane code ... */ } void __init init_IRQ(void) { irq_cannonicalize = indy_irq_cannonicalize; bridge_init(); set_except_vector(0, ip27_irq); } #ifdef CONFIG_SMP /* * This following are the global intr on off routines, copied almost * entirely from i386 code. */ int global_irq_holder = NO_PROC_ID; spinlock_t global_irq_lock = SPIN_LOCK_UNLOCKED; extern void show_stack(unsigned long* esp); static void show(char * str) { int i; int cpu = smp_processor_id(); printk("\n%s, CPU %d:\n", str, cpu); printk("irq: %d [",irqs_running()); for(i=0;i < smp_num_cpus;i++) printk(" %d",local_irq_count(i)); printk(" ]\nbh: %d [",spin_is_locked(&global_bh_lock) ? 1 : 0); for(i=0;i < smp_num_cpus;i++) printk(" %d",local_bh_count(i)); printk(" ]\nStack dumps:"); for(i = 0; i < smp_num_cpus; i++) { unsigned long esp; if (i == cpu) continue; printk("\nCPU %d:",i); printk("Code not developed yet\n"); /* show_stack(0); */ } printk("\nCPU %d:",cpu); printk("Code not developed yet\n"); /* show_stack(NULL); */ printk("\n"); } #define MAXCOUNT 100000000 #define SYNC_OTHER_CORES(x) udelay(x+1) static inline void wait_on_irq(int cpu) { int count = MAXCOUNT; for (;;) { /* * Wait until all interrupts are gone. Wait * for bottom half handlers unless we're * already executing in one.. */ if (!irqs_running()) if (local_bh_count(cpu) || !spin_is_locked(&global_bh_lock)) break; /* Duh, we have to loop. Release the lock to avoid deadlocks */ spin_unlock(&global_irq_lock); for (;;) { if (!--count) { show("wait_on_irq"); count = ~0; } __sti(); SYNC_OTHER_CORES(cpu); __cli(); if (irqs_running()) continue; if (spin_is_locked(&global_irq_lock)) continue; if (!local_bh_count(cpu) && spin_is_locked(&global_bh_lock)) continue; if (spin_trylock(&global_irq_lock)) break; } } } void synchronize_irq(void) { if (irqs_running()) { /* Stupid approach */ cli(); sti(); } } static inline void get_irqlock(int cpu) { if (!spin_trylock(&global_irq_lock)) { /* do we already hold the lock? */ if ((unsigned char) cpu == global_irq_holder) return; /* Uhhuh.. Somebody else got it. Wait.. */ spin_lock(&global_irq_lock); } /* * We also to make sure that nobody else is running * in an interrupt context. */ wait_on_irq(cpu); /* * Ok, finally.. */ global_irq_holder = cpu; } void __global_cli(void) { unsigned int flags; __save_flags(flags); if (flags & ST0_IE) { int cpu = smp_processor_id(); __cli(); if (!local_irq_count(cpu)) get_irqlock(cpu); } } void __global_sti(void) { int cpu = smp_processor_id(); if (!local_irq_count(cpu)) release_irqlock(cpu); __sti(); } /* * SMP flags value to restore to: * 0 - global cli * 1 - global sti * 2 - local cli * 3 - local sti */ unsigned long __global_save_flags(void) { int retval; int local_enabled; unsigned long flags; int cpu = smp_processor_id(); __save_flags(flags); local_enabled = (flags & ST0_IE); /* default to local */ retval = 2 + local_enabled; /* check for global flags if we're not in an interrupt */ if (!local_irq_count(cpu)) { if (local_enabled) retval = 1; if (global_irq_holder == cpu) retval = 0; } return retval; } void __global_restore_flags(unsigned long flags) { switch (flags) { case 0: __global_cli(); break; case 1: __global_sti(); break; case 2: __cli(); break; case 3: __sti(); break; default: printk("global_restore_flags: %08lx\n", flags); } } #endif /* CONFIG_SMP */